The present invention relates to a wireless communication system for mobile communication, and more particularly to a wireless communication system capable of selecting an optimal wireless communication service among multiple different wireless communication services.
One of the known methods of connecting to the Internet using a mobile terminal such as a notebook computer and a PDA from outside the office or home is to utilize a mobile phone service. While the method is advantageous in that the service area is large, it has a problem that the communication speed is relatively slow.
As a new method of connecting to the Internet with a mobile terminal, a so-called hot-spot service has now been provided, which can be available by installing an access point for a wireless LAN in a people-gathering public space such as a department store or a coffee shop. While this method is advantageous in that the communication speed is relatively high in comparison with that of a mobile phone service, it has a problem that the service area is relatively small in comparison with that of a mobile phone service.
Thus, the present situation is that several hot-spot service areas providing high-speed communication service are scattered within a mobile phone service area providing low-speed communication service. In order to take advantage of the merits of both, it is conceivable to mount a radio transceiver for mobile phone services and a radio transceiver for hot-spot services onto a mobile terminal to enable the mobile terminal to usually connect to the Internet via a mobile phone service and switch from Internet connection via the mobile phone service to Internet connection via a hot-spot service when it is within the service area of the hot-spot service.
As a prerequisite for switching from Internet connection utilizing a mobile phone service to that utilizing a hot-spot service, it is necessary to check if the mobile terminal is within the service area of the hot-spot service. One method of this is to check if the mobile terminal is within a hot-spot service area using its radio transceiver for a hot-spot service while using its radio transceiver for a mobile phone service to connect to the Internet.
By using the radio transceiver for a mobile phone service and the radio transceiver for hot-spot service at the same time, however, power consumption of the mobile terminal is considerably increased. Especially, mobile terminals are often battery-operated, and therefore increase in power consumption immediately brings about reduction in battery life, or reduction in available time of the mobile terminal.
The present invention is intended to solve the technical problems mentioned above, and its purpose is to allow reduced power consumption of mobile terminals.
Another purpose is to notify the user that his mobile terminal is within an area where it can be provided with a local high-speed communication service such as a hot-spot service.